Ultrasonic weld pattern for adsorbent containing package

ABSTRACT

Method of preparing an adsorbent containing package and package made thereby. The method comprises providing a mounting surface of the package and heat fusing the mounting surface via ultrasonic welding to provide a multiplicity of depressed hard seal portions and relief surfaces on the mounting surface. The ratio of hard sealed portions to total seal area is within 10-60%.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Continuation-in-Part (CIP) of InternationalPCT Application Number PCT/US01/44618 filed Nov. 27, 2001 anddesignating the United States, which claimed the benefit of prior U.S.Provisional Application No. 60/250,559 filed Dec. 1, 2000.

FIELD OF THE INVENTION

[0002] The invention relates to adsorbent containing packages havingimproved ultrasonically welded seam components with intermittent sealedportions and relief portions.

SUMMARY OF THE INVENTION

[0003] Typically a large area of material is ultrasonically welded toseal the desiccant package closed and provide a means to attach thepackage to the inside of an automotive air conditioning accumulator,condenser or receiver/dryer. Once welded, this large sealed arearestricts the flow of oil and refrigerant thus reducing the oilcirculation efficiency of the ac system. To make a weld, an ultrasonichorn and a smooth faced steel anvil are used to compress the bagmaterials therebetween. Energy is then applied to the ultrasonic hornthus welding the bag material. Typically a smooth faced horn is used toprovide for a continuous smooth weld that is very dense and fluidimpermeable. This invention provides for a texture to be applied to theface of the anvil. This texture produces a pattern weld in the bagmaterial including hard sealed areas where the weld is extremely denseand fluid impermeable and relief areas where the bag material is notwelded and is very permeable.

[0004] Care must be taken to ensure that the seam area comprises theproper proportion of the hard sealed portions and relief portions sothat the weld area will be properly sealed while allowing for desiredpermeability. An additional advantage is that the textured weld reducesthe energy required to produce a weld and thus reduces the cycle time ofthe machine to manufacture the bag.

[0005] The adsorbent material package of the present invention comprisesan elongated pouch or the like adapted for filling with desiccant orother adsorbent medium therein. Preferably, the package is made of aporous, non-woven, material such as a spun bonded nylon material, spunbounded polyester material, or polyester felt. An aperture is providedin one end of the package and is surrounded by an ultrasonically sealedmounting zone. The package aperture is force or snap fit over a flangeor the like associated with the bleed filter that is in turn connectedto the bight portion of the suction tube of the accumulator or similara/c piping structure. In typical accumulator structures, the bightportion is oriented transversely with respect to the longitudinal axisof the cylindrical housing and connects upwardly extending legs of thefluid flow tube.

[0006] A longitudinally disposed seam member is formed along the lengthof the top or bottom side of the adsorbent pouch. This seam includes adouble fabric layer area and may be formed via conventional means suchas heat sealing, ultrasonic sealing, or other electronic sealing orfusing means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a top plan view of an adsorbent material package inaccordance with the invention;

[0008]FIG. 2 is a bottom plan view of the package shown in FIG. 1;

[0009]FIG. 3 is a magnified view of a section of an the mounting zone ofthe package shown by the broken line circle in FIG. 1;

[0010]FIG. 4 is a schematic view of an ultrasonic welding apparatus thatis used to ultrasonically form the mounting zone in accordance with theinvention;

[0011]FIG. 5 is a schematic view of the top surface of the anvil portionof the ultrasonic welding apparatus shown in FIG. 4;

[0012]FIG. 6 is another exemplary embodiment of the mounting zoneaccording to the invention;

[0013]FIG. 7 is another exemplary embodiment of the mounting zone of thepackage according to the invention; and

[0014]FIG. 8 is another exemplary embodiment of the mounting zone of thepackage according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] Turning now to FIGS. 1 and 2, there is shown an adsorbent package20 in accordance with the invention. The top side or surface 42 of thepackage or packet is shown in FIG. 1. Here, the elongated packetmaterial comprises pouch end seams 48, 54 sealing the respectivelongitudinal ends of the package. A longitudinally extending seam 44(FIG. 2) extends longitudinally along the length of the back of theelongated packet and is slightly laterally offset from a longitudinallyextending bisector line extending through the package. This seam 44provides a double thickness of the felt like material used to form thepacket 20 and therefore can be referred to as a reinforcement area.

[0016] The pouch end seams 48, 54 and the longitudinally extendingreinforcement seam 44 define a pouch 50 therebetween adapted to containadsorbent material (not shown) therein.

[0017] The end seam 54 serves as a mounting zone by which the packetwill be attached to the bight tube filter or the like in an accumulator,receiving dryer or condenser. As shown, a centrally located aperture 62is adapted for snap fitting over the bleed filter positioned on thebight tube.

[0018] The mounting zone surrounds the aperture and extends betweentransverse borders 102, 104 of the packet.

[0019] As shown herein, both the mounting zone and the end seam 48 areultrasonically welded to include a multiplicity of spaced, hard sealedareas 106, existing in a sea or matrix of relief areas 108. Morespecifically, as shown, the areas 106 and 108 alternate along vectorsthat are parallel to the longitudinal axis 110 of the packet and alongvectors parallel to a direction perpendicular to the axis 110. The hardsealed areas 106 are highly compressed and relative to the generallyplanar relief areas 108, comprise generally oblong shaped areas ofdepression. These areas 106 are generally indented or depressed at adistance of about 0.030″ relative to the plane of the surfaces 108.

[0020] Preliminary observations reveal that the positioning of themultiplicity of relief areas throughout the mounting zone aids inincreased permeability of fluid including refrigerant, air, moisture andcompressor lubricating oil through the zone. At the same time, themultiplicity of hard sealed areas 106 ensure adequate sealing of theplies of the packet material together.

[0021] In order to make the packet 20, a tubular material is firstprovided. At present, it is preferred to provide a non woven spun bondednylon material for the packet. Presently, this material is availableunder the designation “Cerex PBN2” sold by Cerex, Advanced Fabrics,L.P., Cantonment, Fla. This product is described as a non-woven that ismade by spinning and thermally bonding continuous filaments of nyloninto a “drapable, conformable, textile-like fabric.” Some have alsoreferred to this material as a point bonded nylon.

[0022] The bottom of the material is then sealed via heat seal, or otherelectronic sealing system with the instant ultrasonic sealing methodpreferred, to form a pouch. Then, the desired desiccant is filled intothe pouch. The top longitudinal edge of the packet comprising the abovenoted mounting zone is ultrasonically welded to provide alternating hardsealed and relief areas. At the same time, the bottom half of the nextsucceeding bag in the production run is sealed and the procedurerepeated so that successive bags can be made. After each bag 20 is cut,the mounting aperture is cut in the middle of the mounting zone.

[0023] In accordance with the invention, ultrasonic welding of themounting surface may be performed in conjunction with an apparatus ofthe type shown schematically in FIG. 4. Details pertaining to thisapparatus may be gleaned by review of U.S. Pat. No. 4,767,492, thedisclosure of which is hereby incorporated by reference herein.

[0024] As shown in FIG. 4, the ultrasonic welding apparatus comprises ahorn member 204 and anvil 202 adjacent the horn. As shown, the anvilmember 202 is retractable into a bag engaging and bag release position.In FIG. 4, the apparatus is shown in a position prior to ultrasonicfusion of the mounting surface 54.

[0025] During the fuse bonding process, the mounting surface 54 of thebag is clamped between the horn 204 and cooperating anvil 202. At thesame time, the bottom edge 48 of the packet 20 is firmly grasped withinholding member 206 that may be disposed on a conveyor 208 or the like.

[0026] In accordance with conventional ultrasonic welding methods, thesurface 54 is fuse bonded by the frictional heat caused by ultrasonicvibration of the horn member 204. As is conventional in the art, thehorn 204 is electrically connected to a suitable oscillator and vibrator(not shown). In the apparatus set forth in U.S. Pat. No. 4,767,492, thehorn operates at a vibration frequency of 20 KHz with a power output of1.8 kW.

[0027] Turning now to FIG. 5, the face of the anvil member 202 is shown.Face 210 is provided with a multiplicity of raised portions 212 andplanar relief portions 214. In accordance with the ultrasonic weldingmethod, the edges of the packet that ultimately form the mountingsurface 54 are pressed between the horn and anvil 202 and the raisedsurfaces 212 of the anvil impart the specific heat sealed areas 106 thatare formed in the mounting zone of the packet.

[0028] In one particular embodiment of the invention, (shown in FIG. 3)the hard sealed areas each comprise a generally oblong shape with lengthmeasured along the longitudinal axis of 0.089″ (dimension 301, 302) anda transverse dimension of 0.012″ (dimension 303, 304).

[0029] Although only the anvil member is herein shown to include raisedportions to provide the desired texture to the mounting zone 54 of thepacket, the artisan will appreciate that the horn surface could also beprovided with such a texture forming area or in some cases both theanvil and horn could be provided with complementary texturing surfaces.

[0030] As shown in the exemplary embodiment of FIG. 3, the hard sealedareas are provided in a plurality of horizontally extending rows withthe rows separated by 0.075″ (dimension 305, 306). As positioned alongeach row, a hard sealed area is spaced from its neighboring hard sealedarea by 0.200″ (dimension 307, 308) as measured from one end of a hardsealed area to the corresponding end of an adjacent hard sealed area inthe row.

[0031] In another embodiment shown in FIG. 6, the length of the oblongshaped hard sealed areas is 0.125″ (301, 302) and the transversedimension is 0.03 (303, 304). The other dimensions, namely theseparation between each horizontal row of hard sealed areas (305, 306)and the neighbor spacing between each hard sealed areas (307, 308) isthe same as that shown in FIG. 3. The embodiment shown in FIG. 6 is aStandard weld pattern used on 9.5 ounce felt bags, for instance, whereinthe percentage of hard-sealed weld areas to entire seam area is about23.7%.

[0032] In yet another exemplary embodiment shown in FIG. 7, the length,transverse dimension and neighbor spacing is as shown in FIG. 6.However, the separation between horizontal rows is 0.0625∝ (305, 306) inFIG. 7 compared to 0.75″ in FIG. 6. The embodiment shown in FIG. 7 is aPlus Two, or Delphi, weld pattern used on 7.5 ounce felt bags, forinstance, wherein the percentage of hard-sealed weld areas to total seamarea is about 26.4%.

[0033] In still yet another exemplary embodiment of the mounting zone ofthe package shown in FIG. 8, the hard sealed areas 106 each comprise agenerally circular shape, rather than the generally oblong shape ofearlier described embodiments. The circular hard sealed areas of FIG. 8each have a diameter of 0.06″ (400). The circular hard-sealed areas areprovided in a plurality of horizontally extending rows with the raisedportions separated by 0.10″ (405, 406). Each hard sealed area in a rowis spaced from its neighboring hard sealed area by 0.200″ (407, 408), asmeasured from the diameter (400) of one hard-sealed area to thecorresponding diameter (400) of an adjacent hard-sealed area in the row.The embodiment shown in FIG. 8 is a Dot weld pattern used on felt bagswith tucked ends, for instance, wherein the percentage of hard-sealedweld areas to total seam area is preferably about 14.1%.

[0034] We have found that an area ratio of hard-sealed weld areas tototal seam area of about 10% to about 60% provides an optimum blend offluid impermeable and fluid permeable areas in the seam to providestructural integrity to the package while allowing for adequate fluidflow through the seam. A range of about 10-40% is preferred.

[0035] Although the embodiments shown above are directed to desiccantcontaining pouches or packets designed primarily for use in automotivestructures and systems, the artisan will appreciate that the packets mayalso be used in conjunction with other desiccant containing packagesadapted for a variety of industries.

1. A method of preparing a pouch including an improved fluid permeability fused surface comprising providing a multiplicity of depressed hard sealed portions and relief portions in said fused surface.
 2. A method of preparing an adsorbent containing package including an improved fluid permeability mounting surface for mount of said package to a cooperating support structure of an automotive air conditioning system comprising fusing said package at said mounting surface, and providing a multiplicity of depressed, hard sealed portions and relief portions in said mounting surface.
 3. A method of preparing an adsorbent containing package including an improved fluid permeability mounting surface adapted for mounted disposition adjacent a cooperating support structure of an automotive air conditioning system said method comprising, heat fusing said mounting surface of said package by ultrasonic welding, said ultrasonic welding comprising placing said package between a vibratory horn and a cooperating anvil surface, and providing a multiplicity of raised surfaces on one of said horn and anvil surfaces whereby, during said ultrasonic welding of said package a multiplicity of depressed hard sealed portions and relief portions are formed in said mounting surface.
 4. A method as recited in claim 3 wherein said raised surfaces are provided on said anvil surface.
 5. A pouch comprising a fused surface portion, said fused surface portion comprising a multiplicity of hard sealed portions and relief portions.
 6. An adsorbent containing package, said packet having first and second sealed longitudinal ends, a sealed mounting zone located between said first and second sealed ends, said mounting zone including a fused section of said package and including a multiplicity of depressed hard sealed portions and relief portions formed therein.
 7. An adsorbent containing package as recited in claim 6 further comprising an aperture in said mounting zone.
 8. An adsorbent containing package as recited in claim 6 wherein said multiplicity of depressed hard sealed portions comprise a multiplicity of generally oblong shaped depressions, with adjacent depressions separated by a relief area.
 9. An adsorbent containing package as recited in claim 6 wherein said package is composed of a member selected from the group of polyester felt, spun bonded polyester and spun bonded nylon.
 10. An adsorbent containing package as recited in claim 9 wherein said package is composed of spun bonded nylon.
 11. An adsorbent containing package as recited in claim 6 wherein said oblong shaped depressions are arranged in a plurality of rows transverse to a longitudinal axis passing through said package.
 12. The pouch according to claim 5, wherein the ratio of hard sealed portions to fused surface portion area is within the range of 10-60%.
 13. The adsorbent containing package as recited in claim 6, wherein the ratio of hard sealed portions to total fused section area is within the range of 10-60%.
 14. The adsorbent containing package as recited in claim 8, wherein the oblong shaped depressions are each 0.089 inches in length, 0.012 inches in width, extend in horizontal rows separated by 0.75 inches, and are end-to-end spaced 0.200 inches from an adjacent depression in a common row.
 15. The adsorbent containing package as recited in claim 14, wherein the length of each depression is 0.125 inches and the width is 0.03 inches.
 16. The adsorbent containing package as recited in claim 15, wherein the ratio of hard sealed portions to total fused section area is 23.7%.
 17. The adsorbent containing package as recited in claim 15, wherein the separation between horizontal rows is 0.0625 inches.
 18. The adsorbent containing package as recited in claim 17, wherein the ratio of hard sealed portions to total fused section area is about 26.4%.
 19. The adsorbent containing package as recited in claim 6, wherein the multiplicity of depressed hard sealed portions are circular, with adjacent depressions separated by one of the relief portions.
 20. The adsorbent containing package as recited in claim 19, wherein each depression has a diameter of 0.06 inches, and the multiplicity of depressions extend in horizontal rows separated by 0.10 inches, and each depression is diameter-to-diameter spaced 0.200 inches from an adjacent depression in a common row.
 21. The adsorbent containing package as recited in claim 20, wherein the ratio of hard sealed portions to total fused surface area is about 14.1%.
 22. The method of claim 1, further comprising providing a ratio of hard sealed portions to total fused surface area within a range of about 10% to about 60%.
 23. The method of claim 22, wherein the hard sealed portions are oblong.
 24. The method of claim 22, wherein the hard sealed portions are circular.
 25. The method of claim 2, further comprising providing a ratio of hard sealed portions to total mounting surface area within a range of about 10% to about 60%.
 26. The method of claim 25, wherein the hard sealed portions are oblong.
 27. The method of claim 25, wherein the hard sealed portions are circular.
 28. The method of claim 3, further comprising providing a ratio of hard sealed portions to total mounting surface area within a range of about 10% to about 60%.
 29. The method of claim 28, wherein the hard sealed portions are oblong.
 30. The method of claim 29, wherein the hard sealed portions are circular. 